Spawning occurs between October and January. Mature females usually have less than 100 ova, which suggests a non- ... [details]

The time of spawning varies greatly in different areas. Females with ripe eggs have been observed from May until ... [details]

Breeding occurs from March to May. The eggs are deposited in a cocoon. In the Delta area the pelagic larvae are ... [details]

E. sanguinea breeds in early summer and has planktonic larvae. In the estuarine Delta area juvenile benthic stages ... [details]

Sexually ripe specimens have been observed in April and May. Most probably the larvae have a planktonic ... [details]

Breeding probably takes place in spring (March-June) and the larvae develop in the water column. The species spawns ... [details]

Polynoids, Harmothoe species included, are considered carnivores, feeding on a variety of small infaunal and ... [details]

The sexes are separate and breeding occurs in spring and summer. The larvae have a long planktonic life, lasting ... [details]

L. latreilli probably has a non-pelagic development. Because of its jaws L. latreilli is recorded as a predator ... [details]

The larvae of [Either M. mirabilis or M. johnstoni]occur in the plankton of the North Sea from April-May to August ... [details]

The sexes are separate and individuals breed several times over a number of years in the periods April-May and ... [details]

Breeding occurs in March and August. The species presumably has planktonic larvae.

Analyses of its gut contents ...

The sexes are separate and individuals breed several times over a number of years. Generally, the females breed ... [details]

N. longosetosa breeds from January to early spring and seems to have planktonic larvae. The species is a ... [details]

Pelagic larvae have been found in December, February and April, whereas settling has been observed in ... [details]

Females with ripe eggs have been observed in spring and summer. The planktonic larvae occur in waters with a ... [details]

Main spawning period is short, viz. from June to July. The larvae remain in the plankton for at least four weeks. ... [details]

The sexes are separate and breeding occurs in the period between spring and summer. The species has pelagic larvae. ... [details]

Reproduction takes place in spring and summer. The species has planktonic larvae. P. minuta is considered to be an ... [details]

Reproduction and larval development take place in spring and early summer. The species has a long pelagic stage. ... [details]

The species deposits its eggs in green gelatinous cocoons at the surface of mud flats and probably also on the ... [details]

In spite of its common occurrence there is little information available on its life history or behaviour. S. ... [details]

The larvae of this species have been recorded from March to July, with highest numbers in May-July. Fertilization ... [details]

The sexes are separate. No breeding is observed below water temperatures of 5 °C. Breeding occurs in early spring ... [details]

No information on this species' reproduction is availabie. S. mathildae lives 15 to 20 cm beneath the surface of ... [details]

S. filicornis probably spawns in autumn or winter, releasing large eggs. Planktonic larvae are found from February ... [details]

The planktonic larvae of S. bombyx have been observed in the period April-December, with maximal nurnbers in ... [details]

T. forbesii spawns from November to February. Eggs and larvae are non-pelagic. It is generaily considered to be a ... [details]

On the Dutch Continental Shelf, A. minuta is most frequent in the sandy sediments of the Southern Bight. lt ... [details]

The distribution ofEteone longa ranges from the intertidal zone down to a depth of 30 m. The highest densities are ... [details]

E. sanguinea has a patchy distribution in the sandy sediments of the Dutch Continental Shelf. lt is furthermore ... [details]

N. longissima occurs from the subtidal zone of the Wadden Sea and the Delta area down to a depth of 50 m in the ... [details]

This species is very abundant at the Oyster Ground, where it forms a substantial part of the infaunal biomass. G. ... [details]

L. conchilega is widely distributed in the area, i.e. from the tidal estuaries to the Dogger Bank in the north. ... [details]

L. latreilli is very numerous in the Frisian Front area. The species also occurs in the south-western part of the ... [details]

[Either M. mirabilis or M. johnstoni, long wrongly represented as]M. papillicornis occurs in almost the entire ... [details]

N. caeca occurs in small numbers in a broad region parallel to the coast. lt is even more scarce in the offshore ... [details]

N. cirrosa is a dominant species in the Southern Bight with high densities at the Brown Bank and near the coast. lt ... [details]

The species is common near the coast, in the Wadden Sea and almost the entire Delta area, with high densities in ... [details]

The species occurs in the subtidal zone of the western Wadden Sea, in the shallow waters along the coast and in the ... [details]

This species is quite common at the Oyster Ground. N. latericeus also occurs at a few locations in the ... [details]

O. limacina is found in the Southern Bight, its distribution extending into the marine and central part of the ... [details]

O. fusiformis mainly occurs north of the 30 m isobath up to the Dogger Bank, with the highest densities in the ... [details]

The species shows clear patches with high densities in the South-eastern part of the Oyster Ground, north of the ... [details]

The distribution of P. minuta in the area comprises the brackish waters of the Delta area and the Wadden Sea, the ... [details]

Highest densities are found north of the Wadden islands. lt is found in lower numbers on the Brown Bank, at the ... [details]

A. mucosa occurs near the Dutch coast, from the Voordelta in the south to the Dutch Wadden islands in the north, ... [details]

A widespread species occurring in the subtidal zone of the western Wadden Sea, the Southern Bight, part of the ... [details]

S. squamata is mainly found in the off shore part of the Southern Bight and north of the Wadden islands, and ... [details]

S. armiger occurs in almost the entire area, except for the central part of the Oyster Ground. The polychaete is ... [details]

S. mathildae is most abundant at the Dogger Bank and in a broad zone south of the Frisian Front. The species is ... [details]

S. bombyx is found at almost 50% of all stations sampled. Locally, i.e. to the west and north of the Wadden islands ... [details]

The distribution of T. forbesii comprises the subtidal zone in the western Wadden Sea, the Southern Bight and sorne ... [details]

A. minuta lives in fine and muddy sands mixed with shell fragrnents (Hartmann-Schröder, 1971; Wolff, 1973). [details]

E. longa occurs in all types of sediments, but prefers fine and muddy sand. it is also found in empty tubes and on ... [details]

E. sanguinea has been reported from muddy sand, among algae and also under stones, in kelp holdfasts and among old ... [details]

Its density distribution suggests a preference for substrates with an admixture of mud. [details]

G. cirrhosa shows a preference for the muddier types of sediment as found in the Oyster Ground. [details]

H. glabra lives in fine-medium sand. The species has also been found under stones (Hartmann-Schröder, 1971; Wolff, 1973; ... [details]

L. conchilega mainly lives in mixed sand bottoms and rarely in muddy bottoms. [details]

The species shows a preference for muddy fine sand, but is also recorded from coarse sand, gravel, among sea grass ... [details]

The species prefers fine sands, but also occurs in medium sand mixed with mud (Hartmann-Schröder, 1971; Wolff, 1973). [details]

The species occurs in a wide variety of sediments ranging from coarse to fine muddy sand. [details]

The distribution of N. cirrosa appears to be strongly related to the grain size of the sediment, i.e. it prefers ... [details]

It is not found in the clean sandy substrates in the Southern Bight, in contrast to N. cirrosa and N. longosetosa. ... [details]

This species is reported from a wide variety of sediments, e.g. gravel to coarse sand, on oyster banks and among ... [details]

In the study area N. latericeus shows a clear preference for fine muddy sand. In the southernmost part of the ... [details]

The species prefers medium to coarse sands mixed with gravel or shell fragments. Muddy sediments seem to be avoided. [details]

In the study area O. fusiformis is predominantly found in substrates composed of fine sand with a high mud content, ... [details]

L. koreni lives in many types of sediment, ranging from silt to coarse sand. It is most abundant in mixed bottoms ... [details]

P. minuta prefers to live in very fine sand with more than 10% mud. It is also recorded from under stones, among ... [details]

A. groenlandica lives in fine to coarse sediment with a low content of mud. lt is sometimes found in empty tubes of ... [details]

A. mucosa is abundant in the fine sand areas of the Dutch Continental Shelf. It is also reported from rnuddy ... [details]

S. bonnieri lives in a wide range of sediment types but seems to avoid substrates with a high mud content. [details]

The species lives in fine to medium sand and sometimes in slightly muddy sand. lt shows a very strong preference ... [details]

The species inhabits a wide range of sediment types, ranging from coarse to fine sand. In the study area it prefers ... [details]

The species is most frequently found in fine to very fine sand with little or no mud. [details]

The density distribution of this species suggests a preference for the sandy types of sediment with little mud, ... [details]

Although the species has been found in a variety of sediment types, its density distribution suggests a distinct ... [details]

The species has been mainly found in medium to coarse sand with a very low silt content. T. forbesii is reported as ... [details]

Body minute, up to 15 mm long and made up of around 45 segments. The head is bluntly conical with one small median ... [details]

E. longa has a flattened, slender and elongated body with a length of a few centimetres and up to 200 segments. The ... [details]

A species with a stout, dorsally convex body, up to 30 mm in length and made up of 60-140 segments. The uniform ... [details]

A species with a long, rather flattened body of up to 150 mm in length, with over 200 segments. The head is ... [details]

This species has a flattened body that is oval in outline. lt is composed of up to 38 segrnents and reaches 40 mm ... [details]

The species bears some resemblance to Gattyana cirrosa, i.e. a flattened body, oval in outline and dorsally covered ... [details]

L. conchilega has an elongated body, consisting of two regions. The swollen front region has hair-like as well as ... [details]

This species has a slender, cylindrical body made up of many identical segments with simple, bilobed parapodia. ...

A long, threadlike species that is usually a few centimetres long and composed of up to 150 segments. Two body ... [details]

A member of the family Nephtyidae that can reach a considerable size, viz. maximally 200 mm long with up to 150 ... [details]

A relatively slender nephtyid polychaete of a few centimetres long and about 95 segrnents. Apart from its ... [details]

A robust nephtyid that is markedly rectangular in cross section. Differences with other the Nephtys species are the ... [details]

A slender nephtyid, resembling N. cirrosa macroscopically, but differing from it by the presence of dorsal cirri ... [details]

Like most members of the Capitellidae this is a species with a simple, smooth body, lacking any appendages other ... [details]

Body short, thick and spindle-shaped. Body maximally 50 mm in length and divided into 40 segments. The front part ... [details]

A species with a long, cylindrical body lacking parapodia. The frontal end of the body consists of a circle of ... [details]

This species has a short, conical body, tapering towards the tail. The truncated head bears a characteristic row of ... [details]

A small species, usually not more than 1 cm long. The body is flat, oblong and on the dorsal side covered with soft ... [details]

A relatively large worm with an elongated, flattened body, slightly tapering towards both ends. The head is well ... [details]

This species resembles A. groenlandica, but differs by the shape of the lamellae on the parapodia and its smaller ... [details]